Why not make your own dice site hire a person to do a site for you i think its better a choice if you have a decent amount of bitcoin rather than ivesting into other dice site.
Making a dice site is not as easy as you think. The user would need to create a custom back and front end with great features to attract users. It isn't easy to manage the advertising and the support of the dice site either. As a start, you need to have at least 1000 BTC for people to be interested to try out your dice site. You're responsible to take care of the security management too.